Medical instruments with hollow shafts are used in minimally-invasive medical engineering.
The hollow shaft of the medical instrument is inserted into the body through an incision, and appropriate manipulations are then undertaken in the body through the hollow shaft.
In the process, the inner surface of the hollow shafts is contaminated and has to be cleaned.
One step of a cleaning process consists of guiding a cleaning liquid through the hollow shaft in order to rinse away contamination or pollution adhering to the inner surface. The term cleaning liquid is also understood to include pure rinsing liquids which, for example, can also be provided to rinse remains of a liquid cleaning means, for example, from the inner surface.
Due to the fact that minimally-invasive surgery is widespread, it has become usual to carry out such cleaning and rinsing processes using appropriate machines. To this end, the hollow shafts have to be connected to a connection by means of which the hollow shaft is supplied with the cleaning or rinsing liquid. Since most hollow shafts have a very small clear inner diameter, the connections are provided with a relatively small cross section, for example with a diameter of 3.5 mm.
Cleaning hollow shafts with relatively large diameters, and hence with large lumens, poses problems. Said shafts sometimes also have cross-sectional shapes which differ from circular geometry.
Such medical instruments are, for example, devices to remove the vena saphena magna, that is to say the great saphenous vein, which runs along the lower leg and the thigh and up to the region of the groin. The great saphenous vein is often removed to use it as a transplant in coronary and vessel surgery.
The hollow shaft of this medical instrument has a length of approximately 45 cm and a clear inner diameter of 5 mm.
Operation bronchoscopes are also large-bore instruments, and likewise have lengths in the region of 40 cm and an inner diameter of up to 13 mm.
Cleaning such large-bore hollow shafts with current cleaning or rinsing machines having connections of the order of 3.5 mm cross-sectional diameter and having a rinsing pressure of 0.2 bar is problematic. This is because it is not possible to completely fill the lumen with the cleaning/rinsing liquid and hence ensure that the entire inner surface is sufficiently wetted with the cleaning/rinsing liquid.
The applicant has undertaken trials to the effect of introducing perforated hollow shafts provided with a number of lateral exit openings into the large-bore hollow shafts. The cleaning/rinsing liquid is inserted into the interior of this perforated hollow shaft and emerges radially through the numerous openings. Using this, the inner surface can be sprayed more or less evenly with the cleaning/rinsing liquid. However, it was determined in practical use that even with this auxiliary construction, even application of the cleaning liquid on the inner surface of a large-bore hollow shaft cannot be ensured.
Therefore, the object of the present invention is to remedy this situation and provide a cleaning device by means of which the interior surface of hollow shafts, in particular of large-bore hollow shafts of medical instruments, can be cleaned or rinsed immaculately.